In general, exogenous unmodified nucleic acid molecules, particularly viral nucleic acids, introduced into the cell induce an innate immune response which results in cytokine and interferon (IFN) production and ultimately cell death. It is of great interest for therapeutics, diagnostics, reagents and for biological assays to be able to deliver a nucleic acid, e.g., a ribonucleic acid (RNA), into a cell, such as to cause intracellular translation of the nucleic acid and production of the encoded protein instead of generating an innate immune response. Thus, there is a need to develop formulation compositions comprising a delivery agent that can effectively facilitate the in vivo delivery of nucleic acids to targeted cells without generating an innate immune response.